Defense of Zihua Yang (ChemBio)


Monday december 11, 2023
at 2:30 pm

Pierre et Marie Curie campus
Tower 32-42, room 101

Zihua Yang, a doctoral student in IPCM’s Chembio team and the Laboratoire de réactivité de surface, will present her thesis entitled

« Plasmonic nanoparticle-based enzyme biosensor configurations for the colorimetric assay of phenylalanine »

Phenylketonuria (PKU) is a genetic disorder linked to the enzyme phenylalanine hydroxylase (PAH). This enzyme is involved in the normal metabolism of phenylalanine to tyrosine, so its deficiency causes the accumulation of phenylalanine (Phe) in blood, urine and cerebrospinal fluid and the decrease in tyrosine concentration. When the concentration of Phe exceeds a certain level in the blood, it causes serious neurological problems. Therefore, management of phenylketonuria requires patients to monitor their blood phenylalanine levels, so a rapid test for determination of Phe concentration should be very useful. In this study, we designed several plasmonic nanoparticle-based colorimetric sensors for Phe quantification based on the optical properties of metal nanoparticles. Noble metal nanoparticles exhibit fascinating optical characteristics, mainly due to the localized surface plasmon resonance (LSPR) effect. They absorb and/or diffuse light in the spectral region from visible to near infrared, depending on their size, shape, composition and the condition of their surface. Here, the shift of the LSPR band induced by nanoparticle growth or corrosion was used to set up several enzymatic assay configurations allowing the quantification of phenylalanine by a simple spectrophotometer or even by eye.

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